The subject matter disclosed herein relates to gas separation membranes and, more specifically, to polyimide gas separation membranes.
One method of purifying a gas mixture is through the use of a gas separation membrane. In general, a gas separation membrane relies upon a partial pressure differential across a porous membrane material to selectively drive gas molecules across the membrane. For a gas separation membrane to be effective, the membrane should have a sufficiently high permeance and high selectivity. Permeance is a measure of how easily a particular gas flows across the membrane, while selectivity is a measure of how much more of one component of the gas mixture (e.g., hydrogen) crosses the membrane compared to a second component of the gas mixture (e.g., carbon dioxide). Generally, as the permeance of a membrane increases, the selectivity of the membrane is reduced, making a selective membrane with a high throughput difficult to achieve.